Cross AC Arcing Twin Wires for Decoupled Welding Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional arc welding methods, such as GTAW and GMAW, face limitations in controlling heat input and deposition rate, leading to inefficiencies and weld defects, particularly in overhead welding where filler metal addition is restricted, resulting in reduced productivity and energy waste.
Innovation Solution
The introduction of a new welding method using cross AC arcing twin wires, where a gas tungsten arc is established between the tungsten electrode and the work-piece, and an inter-wire arc between the two wires, allowing for separate control of heat input and deposition rate through adjustable AC current waveforms, ensuring efficient melting of wires with minimal heat input to the work-piece.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If welding current is increased to improve melting rate and welding productivity, then deposition rate is improved, but heat input on the work-piece increases causing weld defects
Solution Approach 1:
The patent divides the welding system into two separate arc sources: a main arc for providing stable heat input to the work-piece, and a filler wire arc for melting the filler wire. This segmentation allows independent control of heat input and deposition rate, enabling high welding speed with controlled heat input to avoid defects.
Solution Approach 2:
The main arc acts as an intermediary that pre-heats the work-piece and creates a stable molten pool, while the filler wire arc separately melts the filler wire. This intermediary main arc enables the filler wire to melt more efficiently with less additional heat, reducing total heat input required while maintaining high deposition rate.
2Productivity
If traditional GTAW is used to fill metal into the groove, then weld quality can be maintained, but deposition rate is low resulting in reduced productivity
Solution Approach 1:
The patent introduces dynamic control of two separate AC current waveforms, one for the main arc and one for the filler wire arc. This dynamic control system adjusts arc parameters in real-time to optimize both deposition rate and weld quality, making the enhanced productivity achievable while maintaining process control.
3Productivity
If filler wire is added in overhead welding positions, then deposition rate can be improved, but heat input control becomes difficult leading to weld defects
Solution Approach 1:
By segmenting the heating function into a main arc (for work-piece heating) and a filler wire arc (for wire melting), the system can independently control heat input to the work-piece even in overhead positions where filler metal addition is restricted in traditional methods.
4Adaptability or versatility
If separate control of arc energy and deposition rate is achieved, then process controllability is improved, but device complexity increases
Solution Approach 1:
The dual-arc system with separate AC power supplies serves multiple functions: the main arc provides stable heat input and molten pool formation, while the filler wire arc melts the filler wire. This multi-functionality achieves superior process controllability of both heat input and deposition rate independently, despite the increased system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables high deposition rates with low heat input to the work-piece, improving process controllability and productivity by decoupling arc energy and deposition rate, reducing waste and enhancing weld quality.
Implementation Method 1
Its arc is established between the tip of the non-consumable tungsten electrode and the work-piece
Implementation Method 2
an inter-wire arc between the two wires, allowing for separate control of heat input and deposition rate
Implementation Method 3
with a shielding gas applied to protect the arc and the weld pool area
Data Source
AI summary
Gas metal arc welding (GMAW) is a widely used process for joining metals. Its main advantage over its competition gas tungsten arc welding (GTAW) is its high productivity in depositing metals. However, to melt metal from the wire to deposit into the work-piece, additional heat is consumed and applied to the work-piece with an uncontrolled fixed proportion to the effective heat that melts the wire. Such additional heat is often in excess of the needed heat input for the work-piece. The side-effects include a waste of the energy, an increased distortion, and possible materials property degradation. This invention is to device a method to transfer this part of heat to melt the wire by adding two wires, which form a pair of arc spots, under a tungsten arc. It also devices a method to assure the arc between the two wires be maintained stable such that the transfer be successfully continuous. The successful continuous transfer improves the energy efficiency, eliminates the adverse effects on the distortion and materials property, and decouples the controls on mass input and heat input on the work-piece.